Card Range To Study

364 Cards in this Set

Radio waves travel at what speed?
1. Speed of sound
2. Speed of light
3. Speed of the Earth's rotation
4. Speed of the Earth's orbit around the sun

2. Speed of light

Which of the following types of energy
CANNOT be seen, heard, or felt?
1. Radio waves
2. Sound waves
3. Heat waves
4. Light waves

1. Radio waves

If a wave has a velocity of 4,800 feet per
second and a wave-length of 5 feet, what
is the frequency of the wave?
1. 9.6 Hz
2. 96 Hz
3. 960 Hz
4. 9,600 Hz

3. 960 Hz

f = v/wavelength
f = 4800/5 = 960Hz

The reception of an AM-band radio
signal over mountains can be explained
by which of the following principles of
wave propagation?
1. Reflection
2. Refraction
3. Diffraction
4. Doppler effect

3. Diffraction

What wave propagation principle
accounts for the apparent increase in
frequency as a train whistle approaches
and the apparent decrease in frequency as
it moves away?
1. Refraction
2. Reflection
3. Diffraction
4. Doppler effect

4. Doppler effect

Varying which of the following wave
characteristics will cause the length of
sound waves to vary?
1. Phase
2. Quality
3. Amplitude
4. Frequency

4. Frequency

Radio-frequency waves CANNOT be seen for which of the following reasons?
1. Because radio-frequency energy is low powered
2. Because radio-frequency waves are below the sensitivity range of the
human eye
3. Because the human eye detects only magnetic energy
4. Because radio-frequency waves are above the sensitivity range of the
human eye

2. Because radio-frequency waves are
below the sensitivity range of the
human eye

The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?

Frequency

The Doppler variation is directly proportional to what radar contact characteristic?

Time-domain plots are used by
technicians to graphically view which of the following waveform parameters?
1. Amplitude versus time
2. Frequency versus time
3. Frequency versus distance
4. Amplitude versus power

1. Amplitude versus time

Which of the following pieces of test equipment should you use to determine
what signals make up a complex signal?
1. Oscilloscope
2. Sweep oscillator
3. Spectrum analyzer
4. Time-domain reflectometer

3. Spectrum analyzer

The action of impressing intelligence upon a transmission medium is referred
to as
1. modulating
2. demodulating
3. heterodyning
4. wave generating

1. modulating

The action of impressing intelligence upon a transmission medium is referred
to as
1. modulating
2. demodulating
3. heterodyning
4. wave generating

1. modulating

The degree to which a cycle has been completed at any given instant is referred
to as the
1. phase
2. period
3. frequency
4. amplitude

1. phase

Which of the following mathematical relationships do you use to figure the period of a sine wave?
1. 1/phase
2. 1/duration
3. 1/frequency
4. 1/amplitude

3. 1/frequency

Which of the following waveform characteristics determines the wavelength
of a sine wave?
1. Phase
2. Period
3. Amplitude
4. Phase Angle

2. Period

2. B
The time during which the pulse is occurring is called PULSE DURATION (pd) or PULSE WIDTH
(pw)

What is the term for the number of complete cycles of ac produced in one second?
1. Period
2. Waveform
3. Frequency
4. Wavelength

3. Frequency

What is the unit of measurement for frequency?
1. Cycle
2. Hertz
3. Period
4. Maxwell

2. Hertz

The value of current of an ac waveform taken at any particular moment of time
is what type of value?
1. Average value
2. Effective value
3. Instantaneous value
4. Peak-to-peak value

3. Instantaneous value

The principal disadvantage of the rhombic antenna is its
1. poor directivity
2. large antenna site
3. low antenna voltage
4. high-frequency inefficiency

2. large antenna site

The unidirectional radiation pattern of the rhombic antenna is caused by which
of the following antenna characteristics?
1. Size
2. Shape
3. Termination resistance
4. Frequency of the input energy

3. Termination resistance

The tendency of EM energy to bend as it passes from a medium of one density to a medium of another
1. Attenuation
2. Reflection
3. Refraction
4. Diffraction

3. Refraction

When EM energy interacts with objects, part of the energy i absorbed by the object and converted into heat.
1. Attenuation
2. Absorption
3. Ducting
4. Diffraction

2. Absorption

The tendency of EM energy to bend around objects in the path of propagation.
1. Attenuation
2. Reflection
3. Refraction
4. Diffraction

4. Diffraction

The natural weakening of a signal as it travels away from the source.
1. Attenuation
2. Reflection
3. Refraction
4. Diffraction

1. Attenuation

The term used for a combination of reflection, absorption, refraction, and diffraction.
1. Attenuation
2. Scatter
3. Ducting
4. Propagation

2. Scatter

EM energy interacts with an object and energy changes direction at an angle that is equal and opposite the angle at which the energy struck object.
1. Attenuation
2. Reflection
3. Refraction
4. Diffraction

The ability of an antenna to transmit and receive more effectively in one direction.
1. Unilateral
2. Directivity
3. Reciprocity
4. Homogenious

2. Directivity

This antenna is most often used to communicate with subs due to the fact the Low Frequency (LF) signals are able to propagate through ice and water.
1. Long Wire Antenna
2. VEE Antenna
3. Rhombic Antenna
4. Log Periodic

1. Long Wire Antenna

This antenna has only one driven element. It restricts the number of frequencies.
1. Uni-Uda
2. Uni-directional
3. Log Periodic
4. Yagi-Uda

4. Yagi-Uda

This antenna has multiple driven elements with each cut to a different length for use with different wavelengths.
1. Multi-Uda
2. Multi-directional
3. Log Periodic
4. Yagi-Uda

3. Log Periodic

When the E-Field runs perpendicular to the the horizon, what is the polarization of the wave?
1. Horizontally
2. Vertically
3. Perpendicular
4. Positive

Which is the only frequency designation system with international standing?
1. Joint Chiefs of Staff (JCS)
2. Intl. Telecom. Union (ITU)
3. Radar Bands
4. FCC

2. Intl. Telecom. Union (ITU)

Which process allows us to move a low frequency up along the spectrum to make transmission easier, and then move it back to its original position on the spectrum for use at the receiver station?
1. Harmonic
2. Nonlinear mixing heterodyning)
3. Linear mixing (heterodyning)
4. Direct Sequence

2. Nonlinear mixing heterodyning)

What is the point-by-point addition of the instantaneous amplitudes of two or more waves?
1. Harmonic
2. Nonlinear mixing heterodyning)
3. Linear mixing (heterodyning)
4. Direct Sequence

What is the purpose of the Reflector array component?
1. Reflect the signal from the driven element
2. Vibrate out of sync with the driven element
3. Deaden the signal from the driven element
4. Vibrate in sync with the driven element

2. Vibrate out of sync with the driven element
3. Deaden the signal from the driven element

What is the purpose of the Director array component in an array antenna?
1. Reflect the signal from the driven element
2. Vibrate out of sync with the driven element
3. Deaden the signal from the driven element
4. Vibrate in sync with the driven element

What device is used to equalize the pressure between the waveguide and the atmosphere?
1. Pressure Equalizer
2. Horn Antenna
3. Directional Antenna
4. Slotted Wavequide

2. Horn Antenna
4. Slotted Wavequide

Name the (3) component waves involved in the modulation process.

Modulating Wave, Carrier Wave, Modulated Waveform

Which wave type will be changed by the modulation process and its purpose is to hold a place along the frequency spectrum?
1. Modulating Wave
2. Carrier Wave
3. Modulated Waveform

2. Carrier Wave

Which wave type will be used to change or modulate the characteristics of another wave?
1. Modulating Wave
2. Carrier Wave
3. Modulated Waveform

1. Modulating Wave

Which wave type is the result of the modulation process and is transmitted?
1. Modulating Wave
2. Carrier Wave
3. Modulated Waveform

3. Modulated Waveform

Which wave type is sometimes called the information wave because it represents the actual data (voice, sound, etc.) to be transmitted?
1. Modulating Wave
2. Carrier Wave
3. Modulated Waveform

1. Modulating Wave

During this process the amplitude of a carrier wave is altered in step with the amplitude of a modulating wave.
1. Frequency Modulation
2. Voltage Modulation
3. Phased Array Modulation
4. Amplitude Modulation

4. Amplitude Modulation

(Amplitude Modulation) - If a modulating wave has a frequency of 5 Hz and a carrier of 100 Hz, what are the new frequencies?

5 Hz above and 5 Hz below the carrier or 95 Hz and 105 Hz

During which modulation process is it desirable to supress a sideband to reduce cost and power consumption?
1. Amplitude Modulation (AM)
2. Frequency Modulation (FM)
3. Both
4. Neither

1. Amplitude Modulation (AM)

What would happen if you suppressed the lower sidebands for AM and FM waves?

AM - Save power and reduce cost; FM - loss of data by eliminating the low amplitudes in the modulating (intelligence) wave.

A _____ is a sudden rise and fall of voltage or current.

Pulse

What is the general term used to describe the magnitude of a pulse?

Pulse Amplitude

What is the term for the major portion of the pulse where the voltage rises rapidly from the min amplitude to the max amplitude?
1. Rise Time
2. Decay Time
3. Trailing Edge
4. Leading Edge

4. Leading Edge

What is the term for the time it takes a pulse to rise from 10 to 90 percent of its maximum amplitude?
1. Rise Time
2. Decay Time
3. Trailing Edge
4. Leading Edge

1. Rise Time

What is the term for the major portion of the pulse where the voltage drops from the maximum amplitude to the minimum amplitude?
1. Rise Time
2. Decay Time
3. Trailing Edge
4. Leading Edge

3. Trailing Edge

What is the term for the time it takes a pulse to drop from 90 to 10 percent of its maximum amplitude?
1. Rise Time
2. Decay Time
3. Trailing Edge
4. Leading Edge

2. Decay Time

What term refers to the physical length of a pulse in free space?

Pulse Width

What is the term for a time measurement that represents the elapsed time from the beginning of a pulse to the next consecutive pulse, or similiar like point-to-point measurement?

Pulse Recurrence Interval (PRI) (Usually digital equip)

What is the term for a measurement of the number of pulses in a 1 second sample of a pulse train?

Which thermal IR property describes the condition of a target that may alter the IR signature of an object due to the properties of the surface matter?
1. Thermal Conductivity
2. Thermal Inertia
3. Thermal Capacity
4. Surface Condition